What do ratings on unidimensional pain and emotion scales really mean? A Multidimensional Affect and Pain Survey (MAPS) analysis of cancer patient responses.

The purpose of the study was to determine what dimensions of pain predicted scores on numerical rating scales (NRSs) of Pain, Anxiety, Depression, and Health Expectation in cancer patients. Seventy-one patients with intra-abdominal cancer responded to the Multidimensional Affect and Pain Survey (MAPS) and rated their pain and emotion on the NRSs. Scores on the Pain NRS were predicted by 41% of clusters in the MAPS Somatosensory Pain Supercluster, but by 100% of clusters in the Emotional Pain Supercluster, and negatively by 51% of clusters in the Well-Being Supercluster. The Anxiety and Depression NRSs were each predicted by only the Intense Pain cluster in the Somatosensory Pain Supercluster, but by all of clusters in the Emotional Pain Supercluster. The findings indicate that cancer patients' emotional state is a strong co-determinant of their sensory pain ratings. Negative emotional aspects of pain contribute also to scores on the Anxiety, Depression and Health Expectation NRSs.